San Diego Unseen: An Urban Portrait
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The press releases and news stories coming from Southern California Edison's coastal power facility on Thursday described a resounding success as it completed the "largest San Onofre plant construction project since early '80s."
What the reports don't say is that in an unrelated incident on the same day, the San Onofre Nuclear Generating Station (SONGS) spilled 60-70 gallons of a solution containing a highly toxic and volatile substance—hydrazine. That information comes from an incident report recorded by the National Response Center, a federal agency charged with cataloging chemical spills. According to the document:
What the reports don't say is that in an unrelated incident on the same day, the San Onofre Nuclear Generating Station (SONGS) spilled 60-70 gallons of a solution containing a highly toxic and volatile substance—hydrazine. That information comes from an incident report recorded by the National Response Center, a federal agency charged with cataloging chemical spills. According to the document:
HYDRAZINE 35% SOLUTION SPILLED FROM A STORAGE TANK DUE TO EQUIPMENT FAILURE. THE MATERIAL ENTERED A SECONDARY CONTAINMENT AREA. STANDING WATER IN THE CONTAINMENT AREA DILUTED THE MATERIAL TO A 24% SOLUTION. 70 GALLONS OF LIQUID WERE RECOVERED FROM THE CONTAINMENT AREA.The NRC was notified seven hours after the accident. Update: A SONGS spokesperson said the proper authorities were notified 36 minutes after the spill occurred.
The plant uses hydrazine to control corrosion and has several precautions in place to control the toxic and unstable chemical, according to reports filed with the state. This isn't the first time SONGS workers spilled the substance; in 2001, anti-nuclear activists were enraged when details were released regarding a smaller, 20-gallon spill of the 35-percent hydrazine solution.
It's not difficult to understand why. According to the U.S. Environmental Protection Agency, hydrazine is extremely dangerous even in small doses (emphasis added):
The company told the NRC that it would be transmitting details of the accident to the other NRC, the Nuclear Regulation Commission, which, ironically, sent Southern California Edison a letter just last month that it was taking it off notice following safety concerns and an investigation initiated in 2008.
Symptoms of acute (short-term) exposure to high levels of hydrazine may include irritation of the eyes, nose, and throat, dizziness, headache, nausea, pulmonary edema, seizures, and coma in humans. Acute exposure can also damage the liver, kidneys, and central nervous system in humans. The liquid is corrosive and may produce dermatitis from skin contact in humans and animals. Effects to the lungs, liver, spleen, and thyroid have been reported in animals chronically (long-term) exposed to hydrazine via inhalation. Increased incidences of lung, nasal cavity, and liver tumors have been observed in rodents exposed to hydrazineThe report says the water was pumped into drums. Presumably, these drums will be disposed of in an off-site location, as they normally do with hydrazine waste, though the waste is usually about half the concentration. A Southern California Edison spokesperson could not be reached on Friday afternoon.
The company told the NRC that it would be transmitting details of the accident to the other NRC, the Nuclear Regulation Commission, which, ironically, sent Southern California Edison a letter just last month that it was taking it off notice following safety concerns and an investigation initiated in 2008.
UPDATE Feb 22, 2011: We received this email from SONGS spokesperson Gil Alexander:
Related Information
San Onofre Nuclear Generating Station personnel notified various regulatory agencies on Thursday, February 17, 2011, of the accidental spill of approximately 70 gallons of diluted 35 percent hydrazine from a chemical holding tank inside the plant’s Protected Area. The spill was fully contained in a bermed area and safely removed to barrels. The incident was unrelated to the return to the steam generator replacement project. Hydrazine is used by the plant to help control and prevent corrosion.Southern California Edison (SCE) StatementThe exact cause of the spill is under investigation. No workers were injured and the spill did not threaten the health and safety of the public.The incident was reported to appropriate agencies 36 minutes after it was determined it was reportable.SCE takes seriously its responsibility to manage substances of this type and will develop lessons learned through the current investigation that are designed to prevent a reoccurrence.
Writer's note: In addition to the update, I've made edits to this story to clarify the amount spilled (60-70 gallons) and that the 2001 spill also involved a solution, not pure hydrazine. SCE insists the spill was unrelated to the retrofit and has clarified that this hydrazine was used to prevent corrosion. We have edited accordingly.
